Constitutive modeling of soil-structure interface through the concept of critical state soil mechanics

The behavior of soil-structure interface can be crucial to the overall response of a soil-structure system. The numerical simulation of soil-structure interaction problem requires proper modeling of the interface. The similarity between the behavior of soil and interface is first analyzed in the present paper. With this similarity, the concept of critical state soil mechanics (CSSM), which has been successfully used in the modeling of soil behavior, is used to develop a constitutive model for soil-structure interface in the framework of generalized plasticity. The model is capable of modeling strain hardening, softening, normal dilatancy and stress-path dependency of interface between sandy soil and structures during shearing. The effects of normal pressure as well as density of sand are captured in the model. The performance of the model is verified with various experimental results. The unified modeling of the behavior of interfaces with different roughness, different density of soil and different normal pressures using the concept of CSSM is also successfully attempted.